1. Technical Field
The present invention relates to a MEMS device, an electronic module, an electronic apparatus, and a mobile unit.
2. Related Art
Heretofore, MEMS devices that detect angular velocity or the like have been known in which a MEMS element is formed on a base substrate and a wiring to be connected to the MEMS element is formed on the base substrate using a MEMS (Micro Electro Mechanical System) technique.
As a method of manufacturing such MEMS devices, for example, a silicon substrate serving as the material of a semiconductor element is bonded by anodic bonding to a base substrate formed of glass or the like. Then, the silicon substrate is etched, while leaving a region of the silicon substrate where a MEMS element as a constituent of the MEMS device is formed and a region of the silicon substrate where a wiring to be connected to the MEMS element is formed, to mold the MEMS element and the wiring, whereby the MEMS device is obtained.
For example, in DENSO TECHNICAL REVIEW, Vol. 5, No. 1, 2000, pp. 39-44 (Non-Patent Document 1), an SOI (Silicon on Insulator) substrate is used as a base substrate. Then, Non-Patent Document 1 discloses a configuration in which in a MEMS device having a MEMS element arranged on the SOI substrate, a wiring using polysilicon as a material for connecting with the MEMS element is embedded in the SOI substrate and the wiring is connected with the MEMS element as a destination. In the SOI substrate in Non-Patent Document 1, a SiO2 layer is provided below the position where the wiring is embedded.
However, the wiring is arranged close to the SiO2 glass substrate or the SiO2 layer. Since SiO2 has a high relative dielectric constant, when the wiring is arranged close to SiO2, a parasitic capacitance (stray capacitance) is likely to occur between wirings. Therefore, either method has a risk that electrical characteristics of the MEMS element are adversely affected by the parasitic capacitance between wirings.